[Python-Dev] PEP 8: Discourage named lambdas? (original) (raw)

Samuele Pedroni pedronis at openend.se
Sat May 3 11:32:38 CEST 2008

Terry Reedy wrote:

Some people write somename = lambda args: expression instead of the more obvious (to most people) and, dare I say, standard def somename(args): return expression

The difference in the result (the only one I know of) is that the code and function objects get the generic name '' instead of the more informative (in repr() output or tracebacks) 'somename'. I consider this a disadvantage. In the absence of any compensating advantages (other than the trivial saving of 3 chars), I consider the def form to be the proper Python style to the point I think it should be at least recommended for the stdlib in the Programming Recommendations section of PEP 8. There are currently uses of named lambdas at least in urllib2. This to me is a bad example for new Python programmers. What do our style mavens think? I found only an example in my personal recent code:

START = "" END = "" TITLEPATTERN = lambda s: "%s" % s

this three are later used in a very few .find() and .replace() expressions in the same module. I suppose my point is that while I agree it should be discouraged and is really silly to do it for the few chars gain, it can be used to some effect in very rare cases.

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